Shape memory materials include materials such as polyurethane foams which can be molded at a temperature above the glass transition temperature of the material, cooled to below the glass transition temperature and de-molded, and upon reheating to the glass transition temperature, the molded material deploys, regaining its original shape. Exemplary such materials include polyurethane foams, which, depending on the free volume of open cell pores in the material, are compacted to less than about 50% of the original volume and heated to lock in the pre-deployment structure. Such compacted foams can expand on heating to about 95% or greater of the original volume.
Deployment of articles for downhole use and prepared from these foams is subject to the ambient thermal condition downhole. In particular, where ambient conditions are relatively cold, and because foams are inherently good thermal insulators and therefore do not generally heat through quickly or uniformly as a function of distance from a heat source applied to one surface of a shape memory material foam, deployment may not occur consistently.